DORSEY: We're just trying to get the certainty for planning.

GARDNER: Brent Dorsey is with Entergy, a major power company based in New Orleans. Entergy broke ranks with its own trade association when it came out in favor of carbon regulation. And it's not because it wants to save the world. Entergy is the country's second-largest generator of nuclear power. That doesn't emit CO2 so if carbon is taxed or capped, it could put nuclear at a competitive advantage. But before Entergy invests in more nuclear plants, company execs wants that "if" resolved.

DORSEY: Until there is certainty in terms of regulation, decisionmakers are going to be faced with either flawed decisions or wrong decisions.

GARDNER: Some companies, like the Aspen Skiing Company, want CO2 regulated because they believe climate change will destroy their industry. Others, like GE, are investing heavily in green technology and may profit from carbon regulation. And then, says regulation critic Marlo Lewis, there's Wall Street.